In prior art solutions, integrated circuits in an electronic device, such as a computer, are synchronised using an external clock, with intentional delays in the signal as appropriate to provide the input channels of all integrated circuits with the same time signal. These systems have contained several channels, all of which could be fed with a time signal.
A prior art solution is illustrated in the publication U.S. Pat. No. 4,847,516, which describes a system where the clock signal can be fed into several signal lines so that a simultaneous signal will go through the lines to load units at the ends of the lines. This is accomplished by means of appropriate delays built into the signal lines to make the signals simultaneous. Publication U.S. Pat. No. 6,055,644 describes a similar multichannel system that makes it possible to feed independent signals into each channel. The system comprises a central clock for generating the main clock signal, as well as several channels that can be connected to the device's inputs or outputs.
Synchronising several integrated circuits is a new problem, because in earlier systems, only one integrated circuit has performed one or more specific tasks. Therefore, the solutions described above do not provide a solution for synchronising several integrated circuits in a system where one or more specific tasks are divided between two or more integrated circuits.